Hot-air furnace



Feb. 6, E923.

FILED JAN. 30. |922.

Wm gfx/h Patented ti, 1923.

DEWETT A. BRUNETT, OF MNNEAPGLIS, MNNESOTA.

HOT-AIR FURNACE.

Application ile. January 30, 1922. Serial No, 532,891.

To ZZ whom 'it may concern:

Be it known that l, Dnwirr A. BRUNnrr, a citizen of the United States.l residing at Minneapolis, in the county of Hennepin and State of Minnesota, have invented certain new and useful lmprovements in Hot-Air Furnaces; and l do hereby declare the following to be a full, clear, and enact description ot the invention, such as will enable others skilled in the art to which it appertains to inake and use the same.

rlChis invention relates to a heating system, and particularly to such a system including an auxiliary device in connection with a furnace. The structure herein disclosed is an improvement upon that disclosed and claimed in Patent No. 1,392,888, granted to me Getober 4th, 1921.

lt is an object oi'r' this invention to provide an auxiliary heating device comprising a secondary combustion chamber and to also provide a conduit leading' from a point adjacent the bottom of said chamber and upwardly through the combustion chamber of the furnace proper and from thence to aV smolre pipe.

1t is a further object or the invention to have the auxiliary heating device as a separate unit and to have the combustion charnber therein `connected to the combustion chamber of the furnace by a conduit and to provide a conduit leading from this conduit to the conduit above mentioned which leadsl from the secondary combustion chamber throughl the combustion chamber of the furnace.

These and other objects and advantages of the invention will be fully set forth in the following description made in connection with the accompanying drawings in which like reference characters refer to the same parts throughout the different views, and in which Fig. 1 is a vertical central section through the device;

Fig. 2 is a top plan view of the same, as seen in Fig. 1;

3 is a horizontal section talren on the line 3 3 of Fig. 1, as indicated by the arrows; y

Fig. L1 is a fragmentary vertical section similar tothe section shown in Fig. 1 shown ing` the lower part of a modifica-tion; and

is a similar vertical section showing the upper part of said modification.

Referring to the drawings, the device comprises a furnace comprising' a ire pot 1, which communicates at its upper end with a combustion chamber formed by a casing 2. ash pit 3 is shown below the tire pot 1 and suitable door structures l are provided t'or the lire pot and said ash pit. rlhe chamber 2 is surrounded by a shell 5 spaced therefrom at the top and sides and extending downwardly to a point some distance below the bottom of the ash pit 3. The casing 2 forms a combustion chamber of the furnace or the so-called primary combustion charnber, and is connected by a conduit 6 to a casing` 7 ci an auxiliary heating device, which casing; and chamber therein form the secondary combustion chamber. The casing 7 is, likewise, surrounded by a shell 8 spaced therefrom at the top and sides and extendingdownwardly below the bottom of the same. lt will be noted that the top and bottom of the casing' 7 are substantially level with the top ot casino; 2 and the bottom of the ash pit, respectively. rllhe adjacent portions of the casings 5 and 8 are connected by walls 10 and these walls,together with the remote sides ot the casings' and 8, extend therefrom, continue downwardly below the bottom oit the ash Dit 3 and casing 8 to provide a common base air chamber 9. the bottom of said walls being illustrated in Fig.

1 as resting upon the ground or loor. The vertical. walls oit the casinos 5 and 8 between the walls 10 terminate at the bottom of the casing- 7 and ash pit 3 and are connected by horizontal portion 11.

A plurality of open-ended and preferably cylindrical conduits 12 extend a short distance into the base air chamber 9 and pass vertically upward about the fire box 1 and ash pit 3 and through the combustion chamber 2, the upper ends terminating flush with the top ot said casing. A plurality of similar open-ended tubes 13 extend a short distance below the casing 7 and pass upwardly therethrough. terminating` at their upper ends substantially flush with the top thereof. rilhe space between the top of casing 2 and shell 5 is divided into a plurality of pockets by radially extending;` partitions 14. These partitions extend from the outer wall of shell 14 inwardly to the wall of a central casing 15 which extends downwardly into the primary combustion chamber or casing 2 being closed at its bottom end` and having a conduit 15a connected to one side thereof adjacent its bottom curving downwardly and passingthrough` the bottom of casing2 and terminating iiush with the bottom of the tube or conduits 12. The radial partitions 14 form pockets between the top of easing 2 and shell 5 in which .pockets is located one of the tubes 12 and the radial partitions 14 are extended` downwardly between the sides of the casing 2 and 5 to a point substantially in line with the bottom of the ash pit 3. These partitions extend inwardly to the re pot 1 and ash pit 3 and form, in effect, vertical passages passing from the base air chamber 9 upwardly around the casing 2 and into the pockets at the top of casing The space between the top ofV casing` 7 and shell 8 is, likewise, divided into pockets by radial partitions 16 which pass inwardly from the wall of shell 8v to the wall of a central conduit 17 extending upwardly from the top of casing 7 and surrounding the upper end of a central tube 13. These radial partitions 16 form pockets with which one of the tubes 13 communicates and the partitions 16 are carried down to the bottom of casing 7, thus forming a series of vertical passages extending upwardly from the base air chamber 9 around the sidesof the casing 7.

A fresh air supply conduit 18 communicates with the front of the base air chamber 9. vertically/extending conduits 19 communicate with the top of shell 8 and the pockets formed therein andare arranged to deliver the heat to the rooms or parts of the building to be heated. The central one of the conduits 19 is connected to the chamber 15. A plurality of similar conduits 20 communicate and connect with the top of shell 8 and with the pockets formed at the top thereof and are, likewise, designed, together with the conduit 17, to deliver the heat to the rooms or part of the building to be heated.

The chamber 7 has, adjacent its top, opposite to the side where conduit 6 connects, a smoke pipe connection 21, provided adjacent the casing 7 with a damper 22. The casing` 7 is also provided adjacent its bottom and preferably on the same side as the .conduit 6, with another conduit 23 which extends horizontally toward shell 5, passes into the same and then extends upwardly through the combustion chamber 2through one of the pockets between partitions 14 and out the top of shell 5 where it again extends horizontally and communica-tes with the smoke pipe conduit 21. Another conduit 24 extends vertically from the top of conduit 6 and communicates with the conduit 23.

Conduit 23 is provided adjacent the casing 7 with a damper 25 and the conduit 24 is provided some distance below the upper conduit 22 with a damper 26. lt will be seen that in t-he described structure, the conduit 23 replaces one of the tubes 12.

In the .operation of the furnace the products of combustion from the lire bon 1 pass intoV the combustion chamber 2 and are here partly consumed. The products of combustion then pass through the conduit 6 into casing 7 or the secondary combustion chamber where the combustion thereof is rendered complete. The air passes into the base air chamber 9 and upwardly through the tubes 12, is heated and delivered into the pockets at the top of the cas-ing 2. Air, likewise, travels through the vertical passage between the partition 1,4 around the ash pit 3, fire boi; 1, combustion chamber 2 and is deliveredA into the pockets above casing` 2. This heated air is then delivered from these pockets into V.the conduits 19 through which it. passes to the rooms `to be heated. Cold air, likewise, passes upwardly through the conduits 13 and is heated by the products of combustion in the seconda combustion .chamber 7 and delivered inte the pockets between the partition 1S t. the top of the casing 7, the central conduit delivering into the central conduit 17. This heated air is then delivered through the ccnduit 17 and to conduit 20'tc the rooms to be heated. Air also passes upwardly around the casing 7, and is heated.

With this structure, practically all of the heat is absorbed and used. As is well known. it is necessary to have the gases passing up the chimney somewhat heated. in order to create the roper draft in the furnace.

VWhen the lire is rst started, either the damper 26 or the damper 22 will be opened and the damper .25 closed. The products of combustion can then pass quickly to the smoke pipe and will not have to take the long course .through the auxiliary heating. device including); the chamber 7. after the fire is well started, the dampers 26 and will be closed andthe damper 25 opened so that the products of combustion must then pass through the secondary `comlmstion chamber 7 of the auxiliary heating device. In my former patent?, conduit was provided leading directly from the bottom of casing 7 to the smoke pipe. Withl this structure a certain degree of heat must be left in the Zeases passing through the auxiliar-f.7 heater or the casing 7 in order to insure a sufficient draft.

lVith the struct-ure above described, using; the conduit 23, thecirculationcan be so arranged in the auxiliary heater that practically all available heat will be extracted from the gra-ses or products of combustion'. rlhese products then, as they pass out and lll) 1,444,163 'riff up through the conduit 23 will be heated by the heat from the primary combustion chamber and raised to a sufficient temperature to give the desired draft in the smoke pipe. it has been found that by this structure, a better control of the heat can be attained. The draft can also be nicely regulated when starting the fire by means of the conduit Qs with the damper therein. lt will, of course, also be understood that the various dempers shown can be opened to Various degrees to control the circulation as desired.

In the modification shown in Figs. et and 5, instead of using the space of one of the conduits l2 for the conduit 523, the tube l2 corresponding to one of the tubes l2 is d and the conduit 23a is connected to the ing 7 and passes into and upwardly through the tube 12a and then upwardly through the pocket at the top of the casing 2 and into tube 19a corresponding to a tube 19. The conduit 23a then passes laterally out of conduit 19a and is connected tothe smolre pipe. The pipe 24 is provided as before described.

F rom the above description it will be seen that applicant has provided a novel form of furnace and one functioning in a novel way.

lt will, of course, be understood that various changes may be made in the form, details and arrangement of the parts without departing from the scope of applicants invention which, generally stated, consists in the matter shown and described and set forth in the appended claims.

V/'hat is claimed is:

l. A heating system comprising a furnace including` a fire pot, a combustion chamber, an auxiliary heating device connected to said combustion chamber, and a conduit leading from adjacent the bottom of said auxiliary heating device extending through the said combustion chamber of the furnace and connected with a smoke pipe.

2. A heating system comprising a furnace including a re pot and combustion chamber, an auxiliary heating device comprising a casing forming a secondary combustion chamber, and aconduit leading from adjacent the bottom of said secondary combustion chamber and arranged to extend upwardly through the combustion chamber of the furnace and adapted t-o be then connected to a smoke stack.

3. A heating system comprising a furnace including a lire pot and combustion chamber, an auxiliary heating device separated from said furnace and including a casing forming a secondary combustion chamber, a conduit connecting said secondary combustion chamber to the combustion chamber of said furnace, a conduit leading from adjacent the bottom of said secondary combustion chamber and arranged to pass upwardly through the combustion chamber of said furnace anfl nected to a smel necting the meA second mentioned c i d: A heating system comprising a furnace including lire pot and combustion chamber communieating` th ewl l casing rounding said first inentio d con'ibustion chamber and spaccil therefrom at the si and top, an au j heating device rate from said furnace an;` comprising a casing forming secondary combustion chamber, a shell surrounding the same and spaced therefrom at the sides and tcp, a common i base air chamber extending beneath sait combustion chambers, a plurality of open ended tubes extending from the common base air chamber through the combustion chamber of the furnace and opening into the space between the same anc the top of the surrounding the same, a alurality of open ended tubes enten-fling from the base air chamber through the secondary combusion chamber, and communicating with the space between the top of the saine and to said shell, a conduit connecting the combustion chamber of the furnace to the secondary combustion chamber, plurality of conduits entending from the space above the first mentioned combustion chamber adapted to carry the heat to the rooms to be heated, a plurality of conduits extending from the space the top of the secondary combustion chamber and adapted to carry heat to the rooms to be heated, a conduiv connected adjacent the bottom of the secondary combus tion chamber extending horizontally through the shell and into the casing surrounding` the combustion chaml er of the furnace and upwardly through the latter and the space at the top thereof, out through the top of the casing surrounding` the same and then en* tending horizontally and acapted to be connected to a smolre pipe.

5. rllhe structure set forth in claim and a conduit connected to the conduit which connects the said combustion chambers and extending to the last mentioneoV conduit haying a damper therein, and a damper in the conduit extending from the bottom of the secondary combustion chamber.

6. A heating system comprising a furnace including a ire pot and a combustion chamber communicating therewith, an auxiliary heating device haring a casing therein foriuing a secondary combustion chamber, a conduit connecting the combustion chamber of the furnace and said secondar combustion chamber, a conduit extending from adjacent the top of the secondary combustion chami ber adapted to be connected to the smoke pipe, a conduit entendi 0 from adjacent the bottom of the secondary combustion chamber and arranged to pass upwardly through the combustion chamber of the furnace then extemliug hmizontnly :md communicang with the conduit adapted to be e011- nected to the smoke stack and enothe Conduit extending upwardly 'from the Conduit connecting' the two combustion Chambers and Communicating with the upper portion of the conduit extending from adje-Geni the bottom of the seeonffu'y combustion 01mmber.

T. The stnctul'e Set fort-h in claim l, and meme 1F01* admttnggag from sa; combustion chamber into seid conduit.

The structure sei 'forth in claim l, amd damper con-oled passage for amtting gas lom said combustien Chambley into said e conduit.

n testlmony Whe'eo my slgna-tue DEVVITT A. BRUNETT. 

